The prevalence of adverse reactions to metal debris (ARMD) associated with metal on metal (MoM) hip arthroplasty has been reported to be as high as 69%. Such findings promoted the development of metal-artefact reducing sequence (MARS)-magnetic resonance imaging (MRI) classifications, with the aim of stratifying soft lesions by severity of disease. The Modified Oxford Classification is a straightforward system that has been shown to correlate with disease progression. The aim of this study was to test the reliability of this classification between observers. Seven observers were recruited, all with a musculoskeletal background. Using the PACS image analysis system, 20 MARS-MRI scans were provided for interpretation. Observers reviewed these scans in random order at two separate intervals over the course of five weeks. They classified them according to the Modified Oxford Classification as: ‘normal’, ‘trochanteric fluid, ‘effusion’, ‘ARMD type 1’, ‘ARMD type 2’ and ‘ARMD type 3’.Introduction
Methods
